Portable power driven tools



Oct. 3, 1961 R. F. WONNEMAN ET AL 3,002,510

PORTABLE POWER DRIVEN TOOLS Filed Oct. 1, 1958 2 Sheets-Sheet l 35 /la37 24 4 54 62 e4 INVENTORS BY gm M Oct. 3, 1961 R. F. WONNEMAN ET AL3,002,510

PORTABLE POWER DRIVEN TOOLS 2 Sheets-Sheet 2 Filed Oct. 1, 1958 9? 2 mmmm n 9 w W m on iv a on 3 2 W m M M v N- z 9 Q Ll- WU 0? 3 a 31% l 8 anmm 2 on 1 3 \Y 2 United States Patent a O 3,002,510 PORTABLE POWERDRIVEN TOOLS Roman F. Wouneman, 9621 Harding Ave., Baltimore,

Md., and Donovan S. Grove, Mount Vista Road, Bradshaw, Md.

Filed Oct. 1, 1958, Ser. No. 764,609 3 Claims. (Cl. 123-195) Thisinvention relatesto portable power driven hand tools of the type usedprincipally for drilling and tapping aunularly shaped holes in variousmaterials. Previous disclosures in the art predicate the usefulness ofthese types of power driven tools on the physical size, horsepower audstability of electric motors, and the immediate availability of variouselectric currents. Much ingenuity has been demonstrated in adaptingelectric motors to t-he requirements of hand tool operations to theextent that their usefulness, their appearances and their limitationsare almost universally known and recognized. The Wide limitations ofthese types of electrically powered motor driven hand tools however, aresubordinated to the immediate requirement for available electric power;and, in areas and locations where electric power is not available, suchtools can hardly be used. To a large extent, this important limitationhas been overcome with the introduction and use of portable combustibleengine driven generators. The present invention was conceived toovercome this severe limitation.

Liquid fuel fed internal combustionengines also have been adapted foruse in a wide variety of portable tools; but, due to the physical sizeand weight limitations of the engine itself their uses have beenherebefore confined to single purpose implements, such as chain saws andvarious gardening mowers, tillers, and the like. Engines of this typehave also been equipped with various types of flexible shaftarrangements so as to provide a degree of versatility in remote areasfor power drilling and sawing. Here, the length of the flexible shaft isa restrictive factor in the more widespread use of such an adaption.

The limitations imposed by the inherent features of electrically poweredhand tools along with the herebefore awkwardness, size and bulk ofconventional internal combustion engines, inspired the design anddevelopment of the present invention.

To simply combine an internal combustion engine with a drill chuck, isan obvious but quite deceptive problem. There were problems involvingcarburetion; fuels, and the type thereof; the ignition system; heattransfer and inertial mechanics. A great deal of original thinking,ingenuity and actual development was expended to overcome these problemsto produce a device which would perform its function and duplicate themany uses and functions of an electrically powered unit.

Therefore, with the foregoing preamble in mind;

It is an object of this invention to provide a self powered drillingmachine of the hand type which does not require a source of electricityforeign to the drilling machine.

It is a further object of this invention to provide a self powered handdrill which is adaptable for drilling annularly shaped holes in variousmaterials; and, which is adaptable for receiving various attachments forcutting and sanding, stirring and pumping liquids; and, in general,which will equal the-number of various uses now being done withelectrically powered hand tools.

It is a further, and related object ofthis invention to provide a selfpowered hand drilling machine which permits its use in remote areas, andon wet and dry surfaces.

It is a further objective of this invention to provide a self poweredhand drilling machine which utilizes either a vaporizable liquid fuel;or, a gaseous fuel; or, a solid 3,002,510 Patented Oct. 3, 1961 fuel; ora liquid fuel, from which combustion energy is utilized as a powersource.

It is a further object of this invention to provide a self powered handdrilling machine which utilizes an air cooled two cycle internalcombustion engine as its power plant.

It is a further objective of this invention to provide a self poweredhand drilling machine which is light in weight, easy to use, and whichwill remain cool while it is being operated.

It is a further objective of this invention to provide a self poweredhand drilling machine, which utilizes an internal combustion engine asit power plant, and which is easy to start and which is capable of beingoperated over a wide range of varying and variable speeds, and varyingand variable torques.

It is a further objective of this invention to provide a self poweredhand drilling machine which can be used in its intended functions in anyplane of operation.

It is a further object of this invention to provide a self powered handdrilling machine powered by an internal combustion engine withexternally located controls relative to a substantially enclosedcombination of working and moving components.

Although the foregoing objectives are described in outline other objectsof this invention will become apparent throughout the annexedspecification and claims.

Referring to the drawings:

FIGURE 1 is a top plan view of the self powered hand drilling machineembodying the present invention.

FIGURE 2 is a transverse sectional view taken along lines 2-2 of FIGURE3, and illustrates the mode of mounting the engine within the machinehousing; and, also illustrates the pivoted flutter arm of an air poweredelectrical switch.

FIGURE 3 is a sectional view in elevation taken along lines 3-3 ofFIGURE 1, and illustrates the arrangement of the various componentswithin the drill housing.

FIG. 4 is a horizontal sectional view taken on the line 4--4 of FIG. 3.

Referring to the drawings, the self powered drill embodying the presentinvention is shown consisting of a combination of main componentswherein all are enclosed in a main hollow housing 10 which is providedwith ventilation slots 11 and a pendant pistol grip portion 19 With aremovable cover 12. A power system consisting principally of acombustible fuel fired heat engine 13, a gear train 14, a fuel tank 15,is enclosed within the cavity 17 formed by the configuration of theouter walls of the main housing 10, and the battery 16 is contained inthe pendant pistol grip portion '19. The exterior geometric shape of themain hollow housing 10* and pendant portion 19 is substantially similarto that of previously disclosed conventional electric motor driven handdrills in that the main housing 10 is an elliptically shaped barrel orcylinder portion closed at one front end with means to support a chuckdrive shaft 18 whilst the pendant portion 19 at the opposite rear end ofthe elliptically shaped barrel or cylinder portion 10 is formed of aconfiguration to provide a hollow pendant pistol like gripping handleportion 19. In order to provide access to the cavity 17 Within the mainhousing '10, wherein the combination of main components are situated asin the electric hand drill, the gripping handle 19 is provided with anaperture 20 and the removable cover 12 which is alfixed in place bymeans of screws 21 one at each corner of the cover 12. In addition tothe ventilating slots 11 which are provided in one side of the mainhousing 10, an additional aperture is also provided in the main housing10 for the control stem and knob 24 of a carburetor needle valve 37. Inthe front wall of the pendant pistol grip portion 19, an opening isprovided for the control lever 22 of a starting switch 23, and in theenclosing cover 12 of the pendant housing '19, another aperture isprovided through which the operating stem 48 of a fuel feed valve 47 isextended to terminate in a valve operating knob 25. The foregoingapertures in the main and pendant housing portions, which are providedas a means of extending the engine controls from the inner cavity to andthrough the housings, are threaded along with the carburetor needlevalve stem 37 and the fuel feed valve stem 48 so as to provide forminute adjustment of either the engine carburetor or the fuel feed.

Referring to FIG. 3, a driven chuck drive shaft 18, which is threaded atone end to receive an expanding jaw chuck 46 of a design andconfiguration previously known and commonly referred to as a Jacobschuck, is rotatably supported in the main housing and extends throughthe front wall thereof, and terminates as a support for a main drivegear 26 which is rigidly afiixed to the shaft .18. A shouldered stud 27is rigidly aflixed to the inner side of the front wall of the mainhousing '10, and rotatably supports two idler gears, one of whichengages the teeth of the main drive gear 26, whilst the other engagesthe teeth of an engine gear 29 which is afiixed to the output crankshaft 30 of the combustion heat engine 13. The foregoing gear train,which consists of the main drive gear 26 a pair of idler gears and acombustion engine gear 29, serve as a reduction type gear train andreduces the relatively high speed of the combustion engine output crankshaft 30 to the chuck drive shaft 18. A conventional type of liquid fueloperated air cooled two cycle engine 13 is supported within the mainhousing 10 in spaced relation to the walls thereof, and is rigidlyafiixed therein on projecting supports 31 by means of screws or othertypes of fasteners. For brevity, no attempt will be made here todescribe the configuration and operation of the heat engine 13immediately in use as an actual reduction to practice as shown, becauseof the wide variety of such engines that are adaptable for thisinvention; and, because the heat engine design art has been thoroughlyexplored and disclosed with the result of the immediate availability ofmany difierent shapes and sizes of such engines for the purpose. Inorder to maintain clarity and simplicity in the present specificationshowever, only one type of liquid fuel fed heat engine, similar to thatused by model airplane enthusiasts is shown and used for exemplificationherein as the power plant in the present invention. This type of enginecontains a carburetor housing 33, -a crankshaft 30, housing 34 and apiston rod in the housing 35 cast integrally with housing 34, withadequate provisions also being present in the engine for an ignitionsystem and fuel feeding system. The heat engine 13, being rigidlyaffixed to the inside surfaces of the main housing 10 in the mannerdescribed, is situated therein so as to receive the discharge end of afuel line 36 to the carburetor housing 33. of the engine. A fuel tankbeing of a configuration to fit snugly inside the main housing 10 and inthe cavity '17 thereof, is rigidly aflixed to the wall of the mainhousing and is provided with a one way check valve 47 with a stem 48which extends through the wall of the main housing 10 so as to provide ameans whereby additional fuel can be introduced to the fuel tank. A fueltank discharge line 38 is attached to a fuel feed valve 47 which servesas a means whereby the flow of fuel from the tank 15 to the carburetor33 is controlled and controllable by means of the combination of thefuel feed valve seat 39, the stem 48 and operating knob 25. Thecarburetor needle valve stem 37 extends from the heat engine carburetorhousing 33 to and through the wall of the main housing 10 and terminatesin an annularly shaped knob 24 a distance 41 beyond the main housing 10of the drill. The ignition system being substantially enclosed withinthe cavity 17 of the main housing 10 and pendant portion 19 of thedrill, consists of a battery 16, a spark plug or glow plug 32, astarting switch 23, and an air flow switch 42. Energy from the batteryis directed to the spark plug 32 by a system of insulated wires, to andthrough the starting ignition switch 23 to and through the air flowswitch 42 to produce a means whereby when energized, the spark plug orglow plug 32 will spark to ignite and explode the fuel being compressedwithin the piston chamber of the heat engine 13. A battery 16 upon beingenclosed within the hollow pistol like handle 19 at the rear of the mainhousing 10 and retained therein by a battery clip 43, is wired by line51 to the open end terminal of the single pole single throw ignitionswitch 23 on one end, and is grounded to the main housing 10, throughthe pendant portion 19, by means of a wire 44 on the opposite end of thebattery, the wire 44 being rigidly afiixed to both the battery 16 andthe pendant portion 19 integral with the main housing =10. A fan 45rigidly aflixed to the backwardly extending end of the crank shaft 30 ofthe engine 13 is provided there as a means of forcing air to and pastthe engine and also as a means of operating a flutter arm 49 of the airflow operated electrical switch 42, which consists of a rotatableflutter arm 49 and a stationary arm 50. Both, the rotatable flutter arm49 and the stationary arm 50 have electrical contacts 54, 55 rigidlyaflixed thereto and are arranged to complete an electrical circuit whencontacting each other. The ignition switch 23 is wired by line 52 to thecontact 54 insulated on the flutter arm 49 of the air flow switch 42.When not in contact with each other the contacts on the stationary arm50 and the flutter arm 49 are spaced in relation to each other so as toprovide an interruption in the electrical circuit from the ignitionswitch 23 to the spark or glow plug in the engine 13. The contact 55insulated on the stationary arm 50 and is cabled by line 53 to the sparkplug 32 to complete the wiring within the drill housing.

As will be seen from FIG. 4, the arm 50 is part of the bracket 56 withupper and lower shelves 62, 63, FIGS. 2 and 3, having oppositelydisposed upper and lower pivot points 64, 65 that rotatably support theswinging arm 49 between them. A flat leaf spring 60 is fastened to thelower shelf of the bracket 56 as by means of a screw 61. From FIG. 2, itwill be noted that the arm 49 can oscillate in a horizontal plane aboutpivot points 64, 65, under the action of fan 45 and spring 60 to closeand open the battery circuit between contacts 54, 55.

In operation it will be observed that all the components, gearing,engine, fuel, air and ignition system, necessary for the operation ofthe portable self powered hand drill are substantially enclosed withinthe main housing 10 of the drill, and that the controls for the speedand consequent ignition and fuel feed are readily accessible at theexterior for manual and hand transportable operation. It will also beobserved that ventilation of the inner cavity 17 within the main housingis accomplished by reason of the fan 45 which draws atmosphere into thedrill housing 10 from the also apertured handle 19, around and past theengine, and forces the said air to the atmosphere through theventilation slots 11 so provided. In readying the portable drill foruse, a cutting bit or attachment drive shaft is slidably inserted in theJacobs chuck 46 and locked therein by previously known means therefor.The starting switch 23 is closed to partially complete the circuit fromthe battery 16 to the spark plug 32. The fuel feed knob 25 is adjustedslightly so as to permit the free how of fuel from the fuel tank to thecarburetor within the carburetor housing 33. By manually rotating thechuck 46, either with the use of a lanyard, or by friction against aflat surface, a sufiicient amount of compression will build in thepiston housing to provide one of the features necessary to start theengine. At the same time the chuck is manually rotated, the force of theair from the fan 45 will close the air flow switch 49, 50, to completethe ignition circuit from the 'battery 16 to the spark plug 32. Oneswitch, the starting switch operates the On 01f controls of the drill,while the carburetor needle valve 37 controls the air-fuel mixture,while the fuel feed valve 48 controls the output speed and torques to bedelivered from the engine to the chuck. The one way valve 47 attached tothe fuel tank 15 along with the vacuum force feed for the fuel permitsthe drill to be operated in any plane of operation.

Having accomplished our objectives, and having described our invention,we claim:

1. A hand operated portable tool comprising: a ventilated casingstructure with a main hollow barrel housing portion adapted to besupported by the palm of one hand and having at one end thereof a drivenrotatable shaft for driving an implement at the exterior of that end ofthe casing while attached to the shaft and reduction gearing on theinside of the casing alongside said end for driving said shaft, and apendant hollow pistol grip handle housing portion at the opposite end ofthe main housing portion for holding the tool in operation solely by thegrasp of the other hand, means for supporting a renewable supply ofcombustible fuel on the inside of the main housing above the pendanthousing portion, a combustible fuel fired heat engine mounted on theinterior of the main housing in spaced relation to the casing thereof ata region intermediate the fuel supply supporting means and the reductiongearing, said heat engine including a cylinder with a piston and a crankshaft connected with the reduction gearing, and ignition means for thefuel to the cylinder, an air line and a fuel supply line for thecylinder all located within the main housing and a fuel valve housingwithin the main housing between the fuel supply supporting means and thefuel supply line, with valves inside the main housing for control of theair to the air line and fuel from the fuel valve housing to the fuelline, with control extensions to the outside of said housing for manualcontrol of the valves for air and fuel supply, and a repectacle for astarting battery and a starting switch located within the pendanthousing portion with a control at the exterior of the pendant portionfor starting connection with the ignition means for the cylinder.

2. A tool as claimed in claim 1, and in which the heat engine is asolely air cooled two-cycle internal combustion engine with a singleignition plug devoid of other ignition means than the starting switchand battery, and in which valves for the control of air and fuel aresimple needle valves manually adjustable by the control extensions atthe exterior of the casing structure.

3. A tool as claimed in claim 1, and which includes a fan rotatable withthe crank shaft in the main housing portion at the exterior of theengine in position to flow air over the engine, and an air flow flutterswitch operable into closing position by the air from the fan forclosing and opening a circuit from the starting switch to the ignitionmeans for the engine.

References Cited in the file of this patent UNITED STATES PATENTS2,479,750 Lewandowski Aug. 23, 1949

